If you want a serious answer, then I don't agree with you - and I don't think RAID is a particularly cost effective (or good) solution for home use. To do RAID properly you should have at least two identical boxes (since you're introducing an extra point of failure in the box/controller itself) and then have some backup strategy. I think backups are also more difficult to organise if you have a large amount of contiguous disk space compared with separate drives, which can be quickly duped onto another of the same size.
Additionally, in my experience RAID boxes for less than £500 generally have cheezy PSUs, underpowered CPU and nasty small fans. £1000 for two of these even before you start adding disks or thinking about backup is money poorly spent. RAID is also at its best when used as a solution to maximise uptime - not a data integrity solution (where I don't believe it's cost effective in a home context).
Which RAID boxes do you own? How many of them?
Housing disks in a Mac Pro means you have them in an excellent PSU and temperature controlled environment which runs quiet, and has very fast access. I run multiple 2 and 2.5TB disks JBOD - and use a 2 bay WeibeTech caddyless hot-swap enclosure to enable a rotating backup strategy onto same-sized disks (including offsite). I'd rather spend my money on more and better backups than some slow RAID enclosures (seriously, are you getting more than 30MB/s?).
I also don't have a team on my network. Just me.
Oh yes - and running Unix servers on the Pro using VMWare sure beats the hassle of running PCs across the network. Snapshots and backing up are a cinch too - since the whole environment lives in a single file.
Can you set up a backup solution for me?!
Seriously, I own a Qnap also. 2 sets of mirroring drives in it and I've never been as nervous as I was when one of them failed. It keeps me up at night when I hear the slightest sound coming out of the enclosure........
It's also quite slow and often fails when I try to move large files over to it.......just not as stable as I would have liked.
As far as price....well, that is what I felt it had going for it. Price and ease of use (in my mind at least). If I had the computer skills to properly set up a RAID using my Mac Pro I'd probably do that for my main storage with the Qnap used as a secondary backup that can be used while the Mac Pro is off.